Communication skills enhance through practice. Consequently, a person who relies heavily on texting to communicate, can impair his or her ability to communicate in other ways. By focusing too heavily on texting, a person likely forgoes other forms of communication, negatively impacting his or her ability to undertake those types of exchanges as effectively.
Much of communication exists in nonverbal cues and signals. Without the feedback from another person's gestures and facial expressions, conversations become robotic, even inhuman, in nature, creating a generation of texters with little to no affect during live conversation, which detrimentally spills over into other areas of life as well.
One of the disadvantages of texting is that doing it frequently makes a person comfortable with communicating with someone else via messaging. It reduces a person's natural ability to hold a conversation with an individual either over the phone or in person, because that form of communication becomes less natural.
Some people simply do not communicate well through speech. Texting provides an outlet for them to communicate in a way that is more effective for them. Texting, therefore, is not a compromising form of communication but an alternate one that likely has little effect on a person's ability to communicate in other ways.