My thoughts on both sides:
1a) Your right to "have fun" does not trump the rights of 4-9 other people to have fun. Play practice, co-op, customs, queue with friends, or even ask if your teammates are ok with you trying out something different.
1b) Be open-minded. Focus on improving your own play rather than on the outcome of a game with randos.
2a) You are not a master theorycrafter. Unless you are playing the game at a high level, you should not be trying out off-meta picks/builds when it is impacting the outcome for other people. Learn the game first; then experiment.
2b) You have a right to question questionable picks/builds in a polite manner. You have a right to offer advice when a player is doing poorly. However, understand that your advice is not a command and that you are not dictator of smite.
3a) Consider why trying off-meta picks/builds is how you "have fun". Is it because you want something to blame, other than yourself, when you lose? Playing a new god/build is not an excuse for making poor decisions, having bad mechanics, not communicating, etc.
3b) Consider why you can only "have fun" if you win. Your randos are going to underperform even if they copy the picks/builds/leveling order/rotations of pros. If you are always playing exactly to the meta, then it is more likely that the other team has players that are not than your team having them. Why aren't you winning?
Recent examples from both sides:
a) I queued for normal conquest with 2 friends; the mode we typically play when 3 of us are on. Everyone in chat gets the roles that they want, but our rando solo chooses geb. One of my friends asks "solo geb?" but the player neither asks if we are okay with it nor explains the reasoning. The other team has a baka and our geb is down 0-3 in the first 5min. We do not BM, but make observations that go ignored. This player never asked for advice nor acknowledged that he was single-handedly throwing the game. When we finally managed to carry and pull off a win, the player exclaims in the post game lobby "see, solo geb works!". What could this player have done differently to make the game more enjoyable for everyone?
b) I wanted to master Medusa and was doing solo queue arena. Another teammate had already hovered Neith, so when I selected Medusa she said "Not 2 hunters please <3". This player did not move off of Neith and it was evident that the <3 was an attempt at manipulation because the player then said something along the lines of "or do whatever the **** you want" when I was still hovering Medusa as the clock wound down. I said nothing as the player seemed intent on having a BM war and that would only distract from my goals. We spread 26-6 with an F6@10 and I outperformed the Neith. Would could this player have done differently to make the game more enjoyable for everyone?