I have to agree with the OP for the most part. The amount of grinding a non-member player is subject to is quite obscene. I just started PRO yesterday, played for a couple hours, and my starting Pikachu was only LV 9 by the time I called it a day. I understand that MMO's such as these should be expected to involve grinding of some sort, but the fact of the matter is that these long grinding sessions we are all subject to are not in the books for busy people with relatively little time on their hands. The reason most new MMO's no longer involve an extensive grinding process is because society has changed. People today have busy and stressful lifestyles with little down time, but during the pockets of free time they have, they want to unwind and enjoy the content of an amazing game like PRO. However, like the OP said, these lengthy grinding sessions prevent many of these fellow players from fully experiencing the game, thus decreasing interest and player retention.
With all that said, you could argue that players not willing or able to put in the time required from this grinding should just not play. But instead of alienating a group of people that enjoy the same shared interest, I offer a solution. The developers can increase EXP rates by just a small factor. In this way, players with relatively smaller amounts of time with the game can still enjoy its content, though their Pokémon may be slightly under-leveled, and a certain amount of grinding is still necessary. This is just my two cents on the matter, but personally, it would encourage me and the entourage of Pokémon players in my family to be more engrossed in the game.