You say that reducing the effectiveness of summon is a drawback. To who? My current (when I actually play) and last four characters (at least, since they were Baendra, Hargustin, Sossaphrin, and Thurthath) have all been summoners. Reducing the effectiveness of summoning into a large group is not a drawback imho. Not every reduction in power is a drawback. If assassinate worked 100% of the time and I suggested it shouldn't, would you say it was a drawback because it reduced the effectiveness of assassinate? Clearly not.

Why is it every time someone suggests a change everyone assumes it is complaining? I am not suffering from things being the way they are, but others are. I am suggesting this change because I believe it would make for more interesting and fun gameplay for all. Was adding the other anti-gank code a drawback because it reduced the chance of someone being permabashed?

Summon is a useful tool, but also is a tool that can generate risk free kills by gank. By all means kill by gank, but accept, as a summoner, that you will incur an element of risk to yourself if you do. The change I suggest would mean that instead of death by gank you have an increased chance of those attempting to gank finding themselves having to fend for themselves, or that two groups fight each other in a more even fight. Taking the example where the one imperial got summoned into the group of 8 (was it?) fortress members. Would it have been more fun in that situation if the use of summon had actually backfire and sent the summoners the other way because of the mismatch in numbers? I think so. It would have made a pretty interesting fight actually, instead of an 8 v 1 gank. It would have sent three summoners to the imperial at the inner, whilst the others would have had to break past the outer.

Is it more fun to have a group v group fight or a fight were one group kills each of the others one by one, even if you are on the winning side? Personally, I'd rather win without spamming summon whilst my group rips each unfortunate to pieces in turn.