Take your Pineco and ***** it!
Of the last 14 10K eggs that I've hatched, 11 have been Pineco. These are from eggs that I have collected over a 3 week plus time period, and have come from many different stops, some as much as 25 miles from others.. The other 3 eggs produced one each, Dratini, Gligar and Larvitar (my only Larvitar). The frequency of Pineco is way out of proportion. Especially since I live in a water biome.
Answers
I have only played the game after gen 2 came out, but it is my understanding that 10 km eggs used to be much better than they are now. The risk of hatching Pineco/Mantine/Miltank/Sudowoodoo/Gligar is way too high. I have bought a LOT of incubators so far because I love hatching eggs, but I am starting to wonder whether it is worth it. Almost all of my 5 km eggs are close to worthless, same with 2 km eggs. Only the 10 km eggs can be really good, but chances are still far greater that you get something completely useless.
If Niantic wants people to continue buying incubators they should dramatically improve the quality of the possible 10km and 5km hatches.
I've played since the beginning, and I only spend coins from gyms on incubators. The fun in hatching eggs is the walking and the 'thrill' of what you get, even if it IS worthless to you. I'm just tired of getting the same thing over and over. I've already evolved 2 of them, and I still have over 150 candies for them.