That is kind of a silly statement IMHO. I actually really like glocks. I have a number of 9x19mm glocks including a G17. I also own a number of other 9x19s from a number of other makers. Glocks, and the 17 specifically, are good guns. The thing is there are a number of 'measurables" we can use to compare gun. Weight, size, capacity, reliability, cost, market support and cost, etc. Just using those it isn't apparent to me that the G17 is necessarily "better" than other options. There are of course a lot of things that are preference or dependent on intended use. Is glocks trigger better than the DA/SA sig trigger? That depends on who you ask and how you define better. I prefer the lower bore axis of a Steyr to that of glock. To me the steyr has less felt recoil, shoots a little flatter and lets me be a little faster.
Before you can even begin to claim better you have to identify the criteria you are using to measure that. With guns there is just too much room for personal preference. Any time I hear someone say gun A or B is absolutely the best I cannot help but tune that out as ignorant fan boy talk. Much more so when it is not backed up with any kind of explanation for such a conclussion. Rarely do folks who have any significant amount of time with say the various striker fired guns assert the one is in absolute terms the best. Now if someone tells me they like A or B or for them A or B has proven the best choice for them, or something like that, that is altogether different.
Lastly even if we accept that a Glock would be the best make, why is a 17 the summum bonum of the wonder nine world. Why not a G34 (which I'd actually prefer and to me is a viable choice for anything I'd use a 17 for)? Or a G19 (which for anything I didn't think the G34 was suited for would be my choice over the G17)?
A gun needs to be reliable above all, it needs to be durable, it needs to be reasonably accurate. After that many things start to become a matter of preference and intended use. Many good guns fit the first list. As a G17 owner you would never hear me poo poo the 17, but I scoff at the idea it is clearly better than a steyr, a walther, an M&P, etc., etc.