You're right about some things, but ultimately your strategy on that last game was to literally just snipe me every single cooldown. You skipped mines and mark of the betrayer, you had no snares and even when reg is losing, Shrapnel Mines helps him get his head back above water from 10-12'ish.
That's not to say you didn't snipe a lot... You sniped me at least 15 times before I got the first kill. You sniped at least 26 times total before deciding to afk at the crystal... I understand where you're coming from, I agree that priests are too strong, that HP totals in general are too high, etc. but when it comes down to it I sat behind a tower for almost half the game because of your snipe pressure alone.
You and I drew very different conclusions from that game. It turns out both of us were very frustrated and until the end of the game when you really got upset I had no idea you were so annoyed. The kills I got on you (there were only two in spite of it being a 20 minute game) were revenge to me, a hard-earned reprieve from your plinking away at me all game. In fact, I couldn't even safely leave my tower until I was able to buy both bishops and a fair amount of additional HP.
Also TB isn't worthless. Fire TB might be quite competitive next patch, and hybrids as well as deep frost builds are already quite effective in team games.
But again, the balance on this game certainly isn't perfect, but you seriously played that character with only two tricks: Snipe and autoattack. It's just not a good build.