They saw it as corruption, basically. Here's a contemporaneous article: https://apps.sas.upenn.edu/caterpillar/index.php?action=retr...

> TicoFrut, which is 98% Costa Rican-owned, charges that the environmental services contract is little more than a permit for improper disposal of its foreign-owned competitor's waste. TicoFrut President Carlos Odio says Del Oro should be compelled to build a proper waste-disposal plant just as his company was forced to do in the mid-1990s amid allegations that orange waste from its juicing plant was polluting a nearby river. So TicoFrut teamed up with a high-profile environmentalist and radio host, Alexander Bonilla, and enlisted the support of two prominent congressmen and a few citrus growers in denouncing the Del Oro project. However, none of Costa Rica's conservation groups joined in the attack on Del Oro.

[...]

> One of the ministers they cited was the acting environment minister at the time, Carlos Manuel Rodriguez, who signed the contract on behalf of the government. Rodriguez, an attorney, denied having sat on Del Oro's board but acknowledged representing the company while working in a law firm contracted by the CDC, Del Oro's British owners. The other official, Agriculture Minister Esteban Brenes, acknowledged having sat on Del Oro's board but denied any involvement with the contract.

> TicoFrut also claimed foreign employees of the CDC and, by extension, Del Oro, had received diplomatic immunity as a sweetener to invest, and could thus act with impunity.

> The Costa Rican Ombudsman's Office conducted its own review and declared the contract illegal. In its non-binding ruling, the ombudsman's office said no official studies had been done on the viability of the orange-waste experiment, and that due process had not been followed before the contract's signing

My guess is that Del Oro would have a competitive advantage in its waste disposal costs.

I guess tico fruit is just an asshole. Being sued is usually bad. If you can sue your competitor even better.