That's the reason why we use m43 - we have 2 lenses manufacturers for us to choose.
I know many Olympus users who die die just stick to Olympus lenses. Olympus and Panasonic compete and collaborate at the same time, sticking to just one brand means you will miss many good lenses from the other brand. Olympus users should be more happy because their camera have good IBIS so they can choose any lenses. Panasonic users may miss some of Olympus tele lenses due to lack of IS, such as the 75mm and the upcoming 45-150mm. [GX7 IBIS is a duck]
As a Panasonic camera user, I love Olympus 9-18mm, 12mm and 45mm. If I need to stick to just Panasonic lenses, I won't have any wide angle fast primes. I also can't shoot long exposure using the wide angle Panasonic 7-14mm zoom because it doesn't take filters. Panasonic may have the 42.5 f1.2 coming but that thing will be huge and expensive. The Oly 45 is so tiny and cheap.
Even Olympus will be having a 40-150 f2.8 soon, it is much much bigger than Panasonic 35-100mm f2.8. They are totally different lenses and size will determine which one you prefer.
If you want to stick to Olympus lenses and you need a full frame 50mm focal length, what do you get? Nope, nothing available.
When it comes to m43 camera bodies, you can stick to a brand, but when it comes to m43 lenses, be flexible.

got mine from b&H for about rm800 + shipping. fast and small if only in manual focus.
because we have IBIS, all you need is a mount adaptor and you could even use other makes of lenses even from the big 2.