I understand your frustration, but this is sadly how it must be. When it comes to the games, it's really, really hard to find good donor perks that will be desired without giving them in game advantages, which would be worse and make it more "pay to win" than anything. Kicking players is the one main feature that attracts donors - without it, there would be a lot less donors, and keeping the servers running would be far harder - what with 30 US, 30 EU, 8 CA and 8(?) AU servers...it takes a lot more money to keep these servers running than you might think.
My first 200 wins I achieved without ever donating...I donated for my first time, and despite the fact that I had such a method to get into servers prior, I loved it. The fact that I got into those 500-600 games without donor is amazing, considering I was never donor the entire time...I do not, however, have any idea what it's like to connect now, as I no longer have to go through the painful process of finding one, haven't needed to for at least 3 months - however, I can give tips to getting in:
-The last non-donor spectator user who joined will be the person who is kicked when a donor joins next. (assuming the server is full.) To avoid being kicked, your best bet is to get into the server as soon as possible after it restarts. Watch the server list for servers in deathmatch, add them to your server list, and refresh every now and then (don't do it too frequently - if you refresh too often, you'll get "communication error" and the only way to fix it is to wait about 5 seconds, then refresh again - this can really throw you off if you get it just before the server comes back up.)
-As soon as the server comes up and you are able to connect, simply double click it and you
should make it in without being kicked most times.
-Avoid servers 1-5 in US and EU. (not sure about CA and AU.) The early numbers are the ones the donors will most likely flock to, and sometimes you'll even have full donor games. The larger the number of the server, the less donors you should expect.
The main problem I'm noticing is that users with a not-so-good internet connection may have trouble getting into a lobby soon enough to not get kicked. Most times, (provided you aren't on the early number servers.) if you didn't manage to make it in or were a late joiner, when you know that you tried as soon as you could, you're probably too laggy to even play the games properly anyway. I suggest checking your internet speed on a website like speedtest.net. Anything less than 10 mbps download is probably a bit too laggy to fight properly anyway...sadly, the more and more users that join our servers, the harder and harder it is to get into a server with a semi-slow internet connection. Not much we can do about it, though...My only suggestion is to try to improve your internet connection by any means you can, although the best answer for that is to pay for better internet connection, which assuming you are the average age of players on here, might be out of your reach... (No offense, but I just assume everyone on here is about the average age of players on here unless otherwise stated.

)
But mainly, though, if you donate, you'd never have to worry about this again, and it's also something a lot more people in the average age range of players can do. It supports the servers and gives you some nice perks, including said kick upon joining ability...I know what it's like to be a regular user like you, and so I hate to sound like a greedy jerk, (not that I get any money from donations - I'm not getting payed for this.) but I've never seen an unhappy donator yet, and even with my knowledge to easily get into servers without donor, it was far worth it for me.
I hope this helped a bit. I am sorry to say it, but removing the kicking feature for donors is just not really possible, as it's the really huge reason for people to donate - Sadly, faster internet = more likely to get into the game, and there's not really much we can do about that. (Although admittedly, those with faster internet connection, the ones who are less likely to lag out, are probably the ones we would more like to see in the games - not to say we don't care for those who do, but it's certainly a lot more fun to play in a game where nobody lags during your fight with them causing you to lose or something.)